package org.seckill.service.impl;

import org.apache.commons.collections.MapUtils;
import org.seckill.dao.SeckillDao;
import org.seckill.dao.SuccessKilledDao;
import org.seckill.dao.cache.RedisDao;
import org.seckill.dto.Exposer;
import org.seckill.dto.SeckillExecution;
import org.seckill.entity.Seckill;
import org.seckill.entity.SuccessKilled;
import org.seckill.enums.SeckillStatEnums;
import org.seckill.exception.RepeatKillException;
import org.seckill.exception.SeckillCloseException;
import org.seckill.exception.SeckillException;
import org.seckill.service.SeckillService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.util.DigestUtils;

import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * @description:
 * @author: jason jia
 * @create: 2018-11-07 23:14
 **/
//@Component @Service @Controller
@Service
public class SeckillServiceImpl implements SeckillService {

    private final Logger logger = LoggerFactory.getLogger(this.getClass());
    //依赖注入
    @Autowired
    private SeckillDao seckillDao;
    @Autowired
    private SuccessKilledDao successKilledDao;
    @Autowired
    private RedisDao redisDao;
     //MD5盐值字符串，用于混淆MD5
    private final String slat = "829gsnk*^%*HUIWND)(OOM)(97";
    @Override
    public List<Seckill> getSeckillList() {
        return seckillDao.queryAll(0,4);
    }

    @Override
    public Seckill getById(long seckillId) {
        return seckillDao.queryById(seckillId);
    }

    @Override
    public Exposer exportSeckillUrl(long seckillId) {
        //优化点：缓存优化：超时的基础上维护一致性
        //1、访问reids
        Seckill seckill = redisDao.getSeckill(seckillId);
        if(seckill == null){
            //2、访问数据库
            seckill = seckillDao.queryById(seckillId);
            if(seckill == null){
                return new Exposer(false,seckillId);
            }else{
                //3、放入redis
                redisDao.putSeckill(seckill);
            }
        }
        Date startTime = seckill.getStartTime();
        Date endTime = seckill.getEndTime();
        Date nowTime = new Date();
        if(nowTime.getTime() < startTime.getTime()
                || nowTime.getTime() > endTime.getTime()){
            return new Exposer(false,seckillId,nowTime.getTime(),
                    startTime.getTime(),endTime.getTime());

        }
        String md5 = getMD5(seckillId);
        return new Exposer(true,md5,seckillId);
    }

    private String getMD5(long seckillId) {
        String base = seckillId + "/" + slat;
        String md5 = DigestUtils.md5DigestAsHex(base.getBytes());
        return md5;
    }

    @Override
    @Transactional
    /**
     * 使用注解控制事务方法的有点：
     * 1、开发团队达成一致约定，明确标注事务方法的编写风格
     * 2、保证事务方法的执行时间尽可能短，不要穿插其他网络操作RPC/HTTP请求或者剥离到方法外部
     * 3、不是所有的方法都需要事务
     */
    public SeckillExecution executeSeckill(long seckillId, long userPhone, String md5)
            throws SeckillException, SeckillCloseException, RepeatKillException {
        if(md5 == null || !md5.equals(getMD5(seckillId))){
            throw new SeckillException("seckill data rewrite");
        }
        try{
            //执行秒杀
            int insertCount = successKilledDao.insertSuccessKilled(seckillId, userPhone);
            //唯一：seckillId + userPhone
            if (insertCount <= 0){
                //重复秒杀
                throw new RepeatKillException("seckill repeated");
            }else{
                //执行秒杀逻辑：减库存 产品竞争
                Date nowTime = new Date();
                int updateCount = seckillDao.reduceNumber(seckillId,nowTime);
                if(updateCount <= 0){
                    //没有更新到记录，秒杀结束
                    throw new SeckillCloseException("seckill is colsed");
                }else{
                    //秒杀成功
                    SuccessKilled successKilled = successKilledDao
                            .queryByIdWithSeckill(seckillId, userPhone);
                    return new SeckillExecution(seckillId, SeckillStatEnums.SUCCESS,successKilled);
                }
            }
        }catch(SeckillCloseException e1){
            throw e1;
        }catch(RepeatKillException e2){
            throw e2;
        }catch (Exception e){
            logger.error(e.getMessage(),e);
            //所有编译期异常转化为运行期异常
            throw new SeckillException("seckill inner error:" + e.getMessage());
        }

    }

    @Override
    public SeckillExecution executeSeckillProcedure(long seckillId, long userPhone, String md5) {
        if(md5 == null || !md5.equals(getMD5(seckillId)) ){
            return new SeckillExecution(seckillId,SeckillStatEnums.data_rewrite);
        }
        Date now = new Date();
        Map<String,Object> map = new HashMap();
        map.put("seckillId", seckillId);
        map.put("phone", userPhone);
        map.put("killTime", now);
        map.put("result", null);
        //执行存储过程，result被赋值
        try {
            seckillDao.killByProcedure(map);
            //获取result
            int result = MapUtils.getInteger(map, "result", -2);
            if(result == 1){
                SuccessKilled sk = successKilledDao.queryByIdWithSeckill(seckillId, userPhone);
                return new SeckillExecution(seckillId,SeckillStatEnums.SUCCESS,sk);
            }else{
                return new SeckillExecution(seckillId,SeckillStatEnums.stateOf(result));
            }
        } catch (Exception e) {
            logger.error(e.getMessage(), e);
            return new SeckillExecution(seckillId,SeckillStatEnums.INNER_ERROR);
        }
    }
}
